The present invention relates to a wireless communication terminal. More particularly, it relates to a digital wireless portable information terminal in accordance with Time Division Multiplexing Access (TDMA) communication method.
This type of digital wireless portable information terminals is constituted so as to include a wireless transmitting/receiving section and a data processing section processing data which this wireless transmitting/receiving section transmits and receives. Data processing is performed with a high speed clock (whose frequency is large) so that a CPU in the relevant data processing section operates at a high speed.
In a digital portable information terminal having a built-in CPU which can be operated at such a high speed, it is obviously approved that noises generated with this high speed CPU plunge into the wireless transmitting/receiving section, has bad influence upon operations of the relevant wireless transmitting/receiving section.
Particularly, since the required CPU operation speed becomes higher accompanying with the enhancement of processing performance of a portable information terminal, noises generated has a tendency to increase still more. Therefore, how the deterioration of sensitivity of a wireless section, particularly of a wireless receiving section due to noises can be prevented at a terminal having a wireless communication function is a big problem.
In order to prevent this, a method that a data processing section and a wireless receiving section are completely separated by a shield not to receive interference of noises for the wireless receiving section is often employed. However, accompanying with a tendency of the miniaturization of terminals, the method for noise removal made by this shield has such problems that it needs a space for package and can not obtain an adequate effect of noise removal.